The invention discloses an energy-saving type greenhouse water circulation system. The energy-saving type greenhouse water circulation system comprises a greenhouse, a rainwater collection device and a water treatment system, wherein an underground space is arranged below the greenhouse, a water use unit is arranged in the greenhouse, the greenhouse comprises stand columns and side walls arranged on the foundation, and a ceiling, and the greenhouse is ring-shaped on the whole; a plurality of oblique beams radially distributed are erected on the top of the stand columns, the ceiling is laid on the oblique beams, and the outer edge of the ceiling extends out of an external wall; the rainwater collection device is mounted below the edge of the ceiling; the water treatment system is arranged in the underground space, used for receiving water coming out of the rainwater collection device, and supplying the water to the water use unit, and the water treatment system is a clustered A2O water treatment device, and comprises a plurality of pipe-shaped A2O processing units which are in series-parallel connection in a switchable manner through pipes. The energy-saving type greenhouse water circulation system can be used for collecting, purifying and utilizing the rainwater of the ceiling, and therefore, while energy sources are saved, the purpose of preventing waterlogging is also achieved.